com.github.tomschi.commons.data.dto.rest.AbstractRESTIdentifiableDto Maven / Gradle / Ivy
package com.github.tomschi.commons.data.dto.rest;
/**
* The abstract class {@link AbstractRESTIdentifiableDto} can be used
* for rest data transfer objects with an identifier. This class
* overrides the {@link #equals(Object)} and {@link #hashCode()} method.
*
* @param The type of the id.
*
* @since 0.1.0
* @author Tomschi
*/
public abstract class AbstractRESTIdentifiableDto implements RESTIdentifiableDto {
private static final long serialVersionUID = 1L;
/**
* Indicates if this object is equals to another object.
* For checking this equality the identifier is used.
* Two objects are equal, if the given object is this
* object (this == obj) or the given object
* has the same class like this and both identifiers
* are equal. If identifier is null the
* the method only check if the given object is this object.
*
* @param obj The reference object with which to compare.
* @return True, if obj equals this, else false.
*/
@Override
public boolean equals(Object obj) {
if (getId() == null) return (this == obj);
return (this.getClass() == obj.getClass())
&& this.getId().equals(((RESTIdentifiableDto) obj).getId());
}
/**
* Returns a hash code value for the object. The value
* is generated with the hashcode of the class name and
* the hashcode of the identifier. If the identifier
* is null {@link Object#hashCode()} is called.
*
* @return A hash code value for the object.
*/
@Override
public int hashCode() {
if (getId() == null) return super.hashCode();
return this.getClass().getName().hashCode() * 13 + getId().hashCode();
}
}